ceph: flush pending works before shutdown super

BugLink: https://bugs.launchpad.net/bugs/1834235
Pending works hold inode references, which cause "Busy inodes after
unmount" warning.

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
(cherry picked from commit a57d9064e4ee4e9882b922d0627be3d426004c69)
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 23d9cfba27700e5efc8d40dfea016a3a2f5c46cc..d250b54c30f718ed0689cbf69043e85f91f960fd 100644 (file)
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -656,6 +656,13 @@ fail:
        return ERR_PTR(err);
 }
 
+static void flush_fs_workqueues(struct ceph_fs_client *fsc)
+{
+       flush_workqueue(fsc->wb_wq);
+       flush_workqueue(fsc->pg_inv_wq);
+       flush_workqueue(fsc->trunc_wq);
+}
+
 static void destroy_fs_client(struct ceph_fs_client *fsc)
 {
        dout("destroy_fs_client %p\n", fsc);
@@ -1063,6 +1070,8 @@ static void ceph_kill_sb(struct super_block *s)
        dout("kill_sb %p\n", s);
 
        ceph_mdsc_pre_umount(fsc->mdsc);
+       flush_fs_workqueues(fsc);
+
        generic_shutdown_super(s);
 
        fsc->client->extra_mon_dispatch = NULL;